1. Field
The present disclosure relates to active optical devices using a phase change material.
2. Description of the Related Art
Optical devices, such as a lens, a mirror, or a prism, are variously used for modulating the path of light in an optical system. In general, optical devices are formed of materials having fixed refractive indexes, and the effect the device has on the path of light is based, in large part, on the shape of the device. Accordingly, in order to control the path of light in an optical system in a desired way, complicated structures are often needed.
Such complexity may be addressed by using a spatial light modulator (SLM) capable of performing functions of multiple optical devices. The key function of an SLM is that its refractive index can be controlled according to an external signal. A conventional SLM includes liquid crystal material to achieve such a function. In such SLMs, however, the speed at which the refractive index can be changed may be too slow for many functions, and there is a limitation in the size of the SLM.